The Design And Implementation Of Equivalent Equipment For External System Of Integrated Multi-bus Technology

The telemetry outside system is an important part of the telemetry bomb and launchvehicle，it is also the main way of obtaining the credible and comprehensive flightinformation。The telemetry bomb and launch vehicle require a variety of analog telemetryoutside the system equipment for controlling and measuring parameters in the process ofdevelopment and testing，which is very important to improve the development efficiency ofthe entire project of the system and to ensure the reliability of each subsystem performance.This paper aims to study and achieve the generic equivalent test bed which used to produce ananalog and digital signal which has various kinds of format parameters and to realize theReal-time monitoring of multi-channel data transmission module.This article which is in support of the project“an outside system equivalent of some sizeof model measuring system“makes a further research on the various types of analog anddigital signals of the measurement systems and on the Real-time monitoring of themulti-channel data. This paper based on the diversity of the various types of formatsparameters signal and the real-time detection of a large amount of data studies the mechanismof multi-channel analog and digital signals of different formats, real-time algorithm ofnetwork data transmission on the CAN bus and the scheduling algorithm of multi-channeldata, achieving the measurement requirements to the outside system equivalent.This article based on understanding the research status and development trends of theautomatic test system at home and abroad proposes a design plan on the measurement systemof the equivalent device，clarifies the involved key technologies and establishes an agreementabout the equivalent application layer data communication. This article is based on themodular design concept，including the analog modules, switch modules, digital modules, andthe master of real-time detection module. The analog module is used to produce 26-channelanalog DC signal, sinusoidal AC signal of 3-way and 4-way platform torque current signal；The switch module produces a 21 road instruction signal; The digital module produces RS422asynchronous serial communication data of 3-way specific frame structure. The Master real-time monitoring module is responsible for reading multiple RS422 asynchronous serialcommunication data and the real-time monitoring of CAN bus network. The entire equivalentis working orderly under the control of the harmonization of the host computer，The hostcomputer and the equivalent device communicate through the USB bus interface. It points outthe realization process of the system test. The extensive testing shows that the equivalentdevice measurement system can meet the requirements of mission，realize the exact output ofthe various types of signals and real-time monitoring to the CAN bus network，Finally, thetext makes a summary and outlook to the entire design process.The main innovation of the paper can be summarized as follows:(1) Reliable system of data communication protocolsThe equivalent realization involves the transmission between different types of parametersformat signal and multi-module data. The equivalent designs a system agreement，uses aunified command, status, data frames and data communications algorithms，improving thereliability of data transmission and the stability of the system effectively。(2) Redundant fault-tolerant mechanismThe transmission Command data among various functional modules and the master node keymodules as the CAN use the design of a redundant fault tolerant，handling errors that mayoccur , switching the redundant fault after occurring faults and making sure the whole systemis continuous and good.(3) The improvements of CAN bus network communication protocolThe improvements of the CAN bus communication protocols is made to avoid that thelow-priority data frames may not be long-term lacking the using right of the bus when theCAN bus network data communication is heavy, using the dynamic priority algorithm tomake the Priority data has the opportunity to transfer.(4) The storage and cache of dataTo realize the storage of the Sinusoidal AC quantify data and the cache of the monitoringmodule date，we should make full use of the resources of RAM Block internal the FPGA.(5) Real-time monitoring of multi-channel communication moduleWe design a scheduling algorithm of reading multi-channel data and real-time monitoringto the CAN bus network and multi-channel RS422 data module. Reading real-time channelmonitoring data only by USB bus interface make each channel data transmission in real time, reliable and stable.